Bootstrap 3 grid, does it *really* matter how many columns are in a row?

I have a form layout that has bootstrap 3 form groups on it. I want these form groups in a single column on < small, 2 columns on tablet size break and 4 column on larger screens.

I have it apparently working perfectly, however after doing some reading here what I did seems to violate the supposed rule that every column in a row must add up to 12. However every tutorial and docs I could find always use weasel words like "should" or "ideally" when saying it should add up to 12. There doesn't seem to be a clear guidance here.

More than 12 Columns -> Wraps:

If the total adds to more than 12 columns, as long as the columns are within a row class, they will just wrap to additional rows. A good use case would be a photo grid system where you would like to add tons of photos but don't know how many rows you'll have and would still like to define the number of columns.